Disease risk from regenerated rice

(Baonghean) -In recent years, although the Department of Agriculture has advised farmers not to produce regenerated rice (also known as dead rice), because it can easily degrade the soil, reduce the quality and yield of rice when harvested; however, in the communes of the 5 southern region, Nam Dan district, the area of ​​dead rice from the spring crop is still over 300 hectares...

Mr. Phan Tam in hamlet 4, Nam Phuc commune, in the spring crop of 2012 planted 1.1 sao of rice, achieving a yield of nearly 65 quintals/ha. After the harvest, Mr. Tam did not till the land for the summer-autumn crop but left the old stubble, taking advantage of the time between two crops to continue harvesting the rice. "In the last spring crop, I calculated the stubble so I planted X23 rice, because this is a hard-stubble variety with strong regeneration ability. A few days before harvesting, I applied 7 kg of nitrogen to increase the regeneration of the stubble; at the same time, I continued to keep water in the field and prevent pests and diseases for the rice. After 50 days, I harvested twice (the first time was the regenerated rice, the next time was the rice blooming in the axil of the plant), the yield was calculated to be more than 90 kg/sao" - Mr. Tam said.

Nam Phuc Commune (Nam Dan) leaves 120 hectares unproductive for summer-autumn crop
but to nourish the dead rice.

In Cau Bau field, Nam Trung commune, Mr. Nguyen Dinh Duc (in hamlet 9) after harvesting spring rice also fertilized the old roots to nourish the dead rice on 1 sao of rice, giving a yield of 1 quintal/sao. According to Mr. Duc, to nourish the dead rice for high yield, when the rice is about 80% ripe, harvest deeply, leaving about 20cm of the roots, only about 10 days later the rice will continue to tiller. If you intend to nourish the dead rice, you need to choose the varieties right from the beginning of the season; these are long-term rice varieties, with strong regeneration ability, large bushes, fast flowering, low rate of empty grains such as X21, X23, BTE1... The advantage of dead rice is that it does not require labor to till the land, saves seeds, fertilizers, the field has little weeds, the rice stalks are hard and drought-resistant. After deducting investment costs, the yield of dead rice reaches 1 quintal/sao.

The deep-lying rice fields such as Rao, Chua Hoi, Cau Chay, Trang Nam... in Nam Trung commune currently have more than 100 hectares of rice production for two crops, but this year there are more than 30 hectares that do not grow summer-autumn rice; after the spring crop, people have cleared stubble to nurture the rice husks. According to Mr. Pham Van Phuong, Head of the Agriculture Department of Nam Trung commune: "Previously, most of the rice husks were not invested in and cared for, but were only used to raise ducks or feed buffaloes and cows... But through monitoring many crops, people discovered that the roots of the previous crop continued to grow strong tillers and bloom beautifully. In 2011 alone, some households that took good care of the rice had a yield of 90-100kg of rice per sao. Rice husks have a short growing period, only 50-55 days, do not have to compete in the land preparation stage and avoid small-season floods".

Mr. Thai Dinh Phu, head of Nam Phuc Cooperative, said: Nam Phuc is a commune located in a low-lying area, and the annual summer-autumn crop often fails to meet the planned target. According to the 2012 plan, the commune had to plant 170 hectares of summer-autumn rice, but during the mobilization process, only 55 hectares were planted, mainly in the two high-lying areas of Xuan My and Dong Giong; in addition, people also left 120 hectares to nurture the rice (an increase of 75 hectares compared to 2011). Of the 120 hectares of rice, only nearly 70 hectares are actually in deep, low-lying areas, which are not reliable; the remaining more than 50 hectares in the highlands can be produced, but this year, due to increased investment costs (currently, 1 labor of planting and harvesting is 200,000 VND/sao, labor of pounding the soil is from 130,000 - 150,000 VND/sao), many people abandoned their fields and did not want to do the summer-autumn crop. This form of farming is only a temporary solution for low-lying areas with high risk of flooding. And leaving rice to wither in the short term seems beneficial for the household economy, but if calculating the total income, it is very low. In Nam Phuc commune alone, to let 120 hectares of rice wither achieve an average yield of 1 quintal/sao for an output of 2,400 tons of rice; if the summer-autumn crop is grown, calculated according to the average yield of years usually reaching 2.5 quintals/sao, the total food output will be 6,000 tons of rice.

In the 2012 summer-autumn crop, according to the plan, Nam Dan district restructured 6,300 hectares of rice, but only achieved 5,900 hectares. In addition to the abandoned area, the whole district still has nearly 300 hectares of rice with dead leaves, mainly concentrated in communes outside the dike, such as Nam Kim (85 hectares), Nam Phuc (115 hectares), Nam Trung (34 hectares)... Mr. Nguyen Huu Nhuan - Head of the district's Agriculture Department said: "Dead leaves" is a farming method that the district has advised people not to practice, because the immediate benefits are low but the long-term consequences are dangerous. Dead leaves are an environment for diseases caused by harmful viruses to develop, especially in the complicated situation of yellow dwarf and stunted leaf diseases, while dead leaves are present in the field for a long time (more than 3 months of the previous crop and nearly 2 months of the crop to die), so brown planthoppers have more opportunities to transmit disease-causing viruses than on transplanted rice plants. Thus, after harvesting spring rice, if people let the rice die, they will unintentionally create a bridge for pathogens to reside and harm the next crop...

Ngoc Anh